The present invention relates generally to tensioning devices for allowing a user to apply a tensioning force to a cable, rope, or the like having a first cable end fixed to a load and a second, free cable end adapted to be secured to a fixed anchoring member, such as a cleat, stake, or any of a number of known anchoring members to which the free cable end can be secured in order to secure the load. More particularly, the present invention relates to a tensioning device that is quickly and conveniently installed and used, and that gives the user a significant mechanical advantage in its application.
Frequently, a load is secured in place by way of a cable, wire, rope, or other such elongated flexible member, which in turn can be manually or otherwise secured to a fixed anchoring member. Specific examples of this type of securing arrangement include tarps extending over a load on a truck or other transport vehicle, flags raised on a flagpole, sails on a sailboat, or any of a wide variety of other applications wherein a rope or cable is used to secure and hold a load or some cargo securely in a desired position. Often, such loads are heavy and difficult to manage and secure, and thus various schemes have been employed to gain a mechanical advantage and apply the proper tension on the rope or cable in order to secure the load or cargo.
One of the above-mentioned commonly-used arrangements for tensioning a cable, used in applications where the cable is relatively flexible, involves tying a portion of the cable into a knot having a loop extending therefrom, running the cable around the anchoring member, back through the loop, and then back to the anchoring member where the cable can be securely wrapped. This arrangement functions generally in the same manner as a pulley or block-and-tackle arrangement, giving the user a mechanical advantage in properly tensioning the cable or rope prior to securing its free end to the anchoring member. Unfortunately, however, this arrangement suffers from the disadvantage that the knot is inconvenient and frequently difficult to untie when the load is to be released, as well as causing damage to the cable or rope.
Other devices and contrivances have been commonly used in order to assist the user in tensioning the cable and securing the load, but also suffer from the disadvantages of being inconvenient or difficult to use, or in some cases even resulting in a weakening of a portion of the cable or rope. Thus, the need has arisen for a simple, easily-used device for tensioning a load-supporting cable or rope, with the device capable of being quickly and easily installed, durable in use, and preferably also giving the user a mechanical advantage in order to assist him or her in tensioning the cable. The present invention seeks to provide such a tensioning device that is also inexpensive to manufacture, widely applicable to any of a number of cable tensioning applications, and which has no moving parts in its preferred form.
According to the present invention, a tensioning device is provided for applying tension to a cable, rope, or the like, with the cable having a first cable end fixed to a load and a second, free cable end adapted to be secured to a fixed anchoring member. The tensioning device according to the present invention preferably comprises an elongated rod-like body formed into a generally serpentine or S-like shape, with a pair of oppositely-facing bights and a midportion interconnecting the bights. A first, typically upper end of the body of the tensioning device extends laterally outwardly to form a first rod-like projection, which is referred to as a first horn. The second, opposite end of the body extends generally in the same laterally outward direction to form a second laterally outwardly-protruding horn at the opposite end of the body. The first horn is adapted to receive a first portion of the cable wrapped a plurality of times (preferably at least three times) therearound, with the second horn being adapted to receive a second portion of the cable passing around the second horn (less than once therearound) in order to change directions in which the cable extends. The midportion of the body is adapted to receive a third portion of the cable extending thereunder with the third cable portion being between, and interconnecting, the above-mentioned first and second portions of the cable.
Preferably, the first horn has a friction surface or other discontinuity thereon in order to substantially prevent slippage of the first portion of the cable, which is wrapped a plurality of times around the first horn. The second horn is adapted to allow slidable movement of the second portion of the cable, in a manner similar to that provided by a pulley or block in a block-and-tackle arrangement. Such friction feature on the first horn of the tensioning device can be accomplished by a number of discontinuities formed on the first horn. Such discontinuities can be provided by winding a generally helical rod or wire-like member a number of times around the first horn, with the bights of the helical rod member being serially spaced apart along the first horn a distance such that they receive and frictionally engage serial wraps of the first portion of the cable therebetween. Alternately, the first horn can have ribs, knurling, or any of a number of known surface discontinuities formed thereon in order to form such friction surface. The above-mentioned midportion of the body is spaced somewhat laterally outwardly relative to the bights on opposite sides thereof, with such spacing of the midportion of the body being adapted to receive and guidingly engage or direct the third portion of the cable between the first and second horns.
In a typical installation, the tensioning device is adapted to be installed on the cable with the cable first extending from the load to the first portion of the cable, which is wrapped a plurality of times around the first horn in a serially outward direction, and then to the third portion of the cable, which extends under the midportion of the body to be guided in its proper direction. From this third portion of the cable, the cable then extends to slidably extend around the fixed anchor member, and then back to the second portion of the cable, which slidably extends around the second horn of the tensioning device. From the second horn, the cable then extends to the free cable end, which can be pulled by the user to tension the cable and then secured by way of wrapping or otherwise attaching the free cable end to the anchoring member, thus allowing the user to anchor the load. In such an arrangement, the preferred tensioning device according to the present invention gives the user a mechanical advantage of approximately twice that provided without the tensioning device, less the effects of friction.
Additional objects, advantages, and features of the present invention will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings.